I have carried a DW in the past, I am curently using a S&W 19 on and off. I like the .357.
Why step down to the .38? You have a nice medium frame revolver that should be relitivly pleasent to shoot with a standard .357 loading.
Why use less?
Using .38 loads will change the way the gun performs a bit. I would reccomend finding a single load for the gun that you like. Use it as your primary and as your speed load as well. Consistancy is good.
I like the Winchester 140gr Silver Tip in a 2 - 3" as it seems to flash less in low light and Federal 158 jhp in 4-6", this is strictly a personal preferance.

"Patriotism is supporting your country all the time, and your government when it deserves it." -Mark Twain

2 answers for this one ............

My Main carry weapon is a Glock 33 .357 Sig loaded with Winchester Lawman ammo or Gold dots.I carry it in a Galco IWB Holster.When I am in a different mood I carry a Taurus .38 Snubby in a nemisis pocket holster Loaded with TAP ammo.

The last few months I have been carrying a Beretta 92, though not by choice.

Back in the World, I carry a Glock 26 most of the time. When in exercise or formal clothes, I fill in with a KelTec P3AT.

I bought a Glock 23 from Old Padawan, which I will give a workout in October when I am on leave. If I like it, I will carry that and "allow" my wife to keep the 26, which somehow found its way into her handbag in my absence.